New AP cages rack. Tubs discontinued.

I might try a spacer either top or bottom. Perhaps a bit of PVCx (same material my AP is made from) then perhaps you could router out a space for flexwatt and probes and such and just use a counter sunk screw or two to hold it in place.

Yeah that's what I was going to do. Either wood or something and just make a spacer. A friend of mine used tiles (actual slate) and still used the head tape where it should be and just put the tiles in as spacers. Said the tiles made the heat spread out under the tub for better ambient temps. He never had an issue so well see.